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I am a postdoctoral scholar in the FOCI Center at the University of Washington. I am supervised by Arvind Krishnamurthy and Ratul Mahajan. My research interests are in System Security and Networked Systems.

I am joining UCLA Computer Science in Fall 2024 as a tenure-track assistant professor.

I received my Ph.D. in Computer Science at UC Berkeley. I was fortunate to be co-advised by David E. Culler and Raluca Ada Popa. During my Ph.D., I worked in the Sky Computing Lab (formerly the RISE Lab) and in the Buildings, Energy, and Transportation Systems (BETS) research group in the EECS Department. Prior to that, I received my B.S. in Electrical Engineering and Computer Sciences at UC Berkeley. As an undergraduate student, I worked in the Software-Defined Buildings (SDB) research group, which was the predecessor to BETS.

Teaching

• Instructor for CS 162: Operating Systems and System Programming, Summer 2020, UC Berkeley
• Head GSI (Head Teaching Assistant) for CS 162: Operating Systems and System Programming, Fall 2019, UC Berkeley

Service

• Co-author of the revised UC Berkeley EECS Operating Systems Preliminary Exam Syllabus (2023)
  
  • Organized an effort, among PhD students, to revise the syllabus. It had last been revised in 2005 (18 years prior).
• Co-organizer of the Systems Reading Group, UC Berkeley EECS (2021-2022)
• Creator and organizer of the DARE Research Workshop, UC Berkeley EECS (2021)
• Graduate Admissions Reader, UC Berkeley EECS (2018-2019)
• Subreviewer for SOSP 2023, SOSP 2021, S&P 2020, SOSP 2019, NSDI 2019, and OSDI 2018

Publications

2023

• Rethinking System Design for Expressive Cryptography.
  Sam Kumar.
  PhD Dissertation. University of California, Berkeley.
  Published as Technical Report No. UCB/EECS-2023-194.

• Skyplane: Optimizing Transfer Cost and Throughput Using Cloud-Aware Overlays.
  Paras Jain, Sam Kumar, Sarah Wooders, Shishir G. Patil, Joseph E. Gonzalez, and Ion Stoica.
  20th USENIX Symposium on Networked Systems Design and Implementation (NSDI 2023).

2021

• MAGE: Nearly Zero-Cost Virtual Memory for Secure Computation.
  Sam Kumar, David E. Culler, and Raluca Ada Popa.
  15th USENIX Symposium on Operating Systems Design and Implementation (OSDI 2021).
  Received a Jay Lepreau Best Paper Award at OSDI 2021.

2020

• Performant TCP for Low-Power Wireless Networks.
  Sam Kumar, Michael P Andersen, Hyung-Sin Kim, and David E. Culler.
  17th USENIX Symposium on Networked Systems Design and Implementation (NSDI 2020).
  Received an Applied Networking Research Prize from the IETF/IRTF in 2022.

• Ghostor: Toward a Secure Data-Sharing System from Decentralized Trust.
  (*Co-primary authors) *Yuncong Hu, *Sam Kumar, and Raluca Ada Popa.
  17th USENIX Symposium on Networked Systems Design and Implementation (NSDI 2020).

2019

• JEDI: Many-to-Many End-to-End Encryption and Key Delegation for IoT.
  Extended Version (published as Technical Report No. arXiv:1905.13369 [cs.CR]).
  Sam Kumar, Yuncong Hu, Michael P Andersen, Raluca Ada Popa, and David E. Culler.
  28th USENIX Security Symposium (USENIX Security 2019).

• WAVE: A Decentralized Authorization Framework with Transitive Delegation.
  Michael P Andersen, Sam Kumar, Moustafa AbdelBaky, Gabe Fierro, John Kolb, Hyung-Sin Kim, David E. Culler, and Raluca Ada Popa.
  28th USENIX Security Symposium (USENIX Security 2019).

• Thread/OpenThread: A Compromise in Low-Power Wireless Multihop Network Architecture for the Internet of Things.
  Hyung-Sin Kim, Sam Kumar, and David E. Culler.
  IEEE Communications Magazine, Vol. 57, No. 7 (ComMag July 2019).

2018

• System Architecture Directions for Post-SoC/32-bit Networked Sensors.
  Hyung-Sin Kim, Michael P Andersen, Kaifei Chen, Sam Kumar, William J. Zhao, Kevin Ma, and David E. Culler.
  16th ACM Conference on Embedded Networked Sensor Systems (SenSys 2018).
  Received a Best Paper Runner-Up Award at SenSys 2018.

• Demo Abstract: Bringing Full-Scale TCP to Low-Power Networks.
  Sam Kumar, Michael P Andersen, Hyung-Sin Kim, and David E. Culler.
  16th ACM Conference on Embedded Networked Sensor Systems (SenSys 2018).

2016

• Well-Connected Microzones for Increased Building Efficiency and Occupant Comfort.
  Michael P Andersen, Gabe Fierro, Sam Kumar, Joyce Kim, Edward A. Arens, Hui Zhang, Paul Raftery, and David E. Culler.
  2016 ACEEE Summer Study on Energy Efficiency in Buildings (SSB 2016).

2015

• DISTIL: Design and Implementation of a Scalable Synchrophasor Data Processing System.
  Michael P Andersen, Sam Kumar, Connor Brooks, Alexandra von Meier, and David E. Culler.
  2015 IEEE International Conference on Smart Grid Communications (SmartGridComm 2015).

• Poster Abstract: Well-Connected Microzones for Increased Building Efficiency and Occupant Comfort.
  Michael P Andersen, Gabe Fierro, Sam Kumar, Michael Chen, Leonard Truong, Joyce Kim, Edward A. Arens, Hui Zhang, Paul Raftery, and David E. Culler.
  2nd ACM International Conference on Embedded Systems for Energy-Efficient Built Environments (BuildSys 2015).

Projects and Software

• TCPlp: TCP for Low Power Wireless Networks
  Published at NSDI 2020 (see above)
  Relevant GitHub repositories: Adoption in OpenThread, Code for Reproducibility

• MAGE: Memory-Aware Garbling Engine
  Published at OSDI 2021 (see above)
  Relevant GitHub repositories: MAGE System, Scripts for Experiments

• JEDI: Joining Encryption and Delegation for IoT
  Published at USENIX Security 2019 (see above)
  Relevant GitHub repositories: JEDI Cryptography Library, JEDI Prototype Implementation

• GDPFS: The Global Data Plane File System
  CS 262A Project Report (Spring 2016)
  Relevant GitHub repositories: GDPFS Implementation, FIG Tree Library (C), FIG Tree Prototype (Java)

• Mr. Plotter: The Multiresolution Plotter (Project Page)
  Project Report (published as Technical Report No. UCB/EECS-2018-85)
  Relevant GitHub repositories: Mr. Plotter Web Application, Mr. Plotter Desktop Application, Mr. Plotter QML Library